The present invention relates to the field of data communication, and more particularly to a system and method for hybrid satellite and terrestrial communication.
Modern corporations require systems for effectively and efficiently communicating information between a central site and a multitude of geographically dispersed related entities. For example, a petroleum corporation may have its headquarters located in Houston, Texas, and thousands of franchise station locations dispersed throughout the country, or throughout the world. The central corporate headquarters may desire to transmit information to some or all of the remote franchise stations, and the franchise stations may desire to reply to the headquarters"" transmission.
One method for communicating between a central site and a plurality of remote sites is to use two-way satellite communications. Communicating information from a central site to a plurality of remote sites can be very effective, particularly where the remote sites are numerous and geographically dispersed, and especially where the central site desires to transmit a common signal to all sites simultaneously. A problem with this approach, however, is that return communications (remote site to central site) are expensive. This expense can be attributed, for example, to the high cost of satellite equipment that must be capable of transmitting as well as receiving information, as well as the cost of purchasing valuable satellite bandwidth. The satellite bandwidth expense is particularly troubling where each remote site is transmitting only a few bits of information, such as a conformation of receipt of the central site""s signal. In that case, having thousands of remote sites each purchasing a channel of satellite bandwidth to transmit a few bits of information is extremely wasteful. Still another problem with this method is that conventional satellite communications do not allow for performance monitoring or flow control of the signals being broadcasted.
In accordance with the present invention, a system and method for hybrid satellite and terrestrial communication are provided that substantially eliminate or reduce disadvantages or problems associated with previously developed systems and methods.
In one embodiment, a system for communicating information between a central site and a remote site includes a central network access device operable to receive a broadcast signal from the central site and to condition the broadcast signal to facilitate its transmission to the remote site using a satellite system. The central network access device is further operable to receive from a wide area network an incoming signal originating from the remote site, and to condition the incoming signal for receipt by the central site.
Technical advantages of the present invention include the provision of a system and method using a satellite system to communicate broadcast signals from a central site to one or more remote sites, and a wide area network to communicate incoming signals from the remote sites back to the central site. The invention provides a highly effective system for two-way communication between a central site and one or more remote sites, while eliminating high costs associated with conventional two-way satellite communication systems. With respect to broadcast signals from the central site to the remote sites, the invention capitalizes on the distance insensitivity and common signal broadcast capabilities of satellite systems. On the return signal side, the invention takes advantage of the significant flexibility and scalability of wide area network communication.
The invention provides an advantage of facilitating functions such as performance monitoring and flow control of signals in either direction. If conservation of bandwidth is important, an encapsulator within the central network access device may be deactivated, resulting in central site transmitting a nailed-up version of the broadcast signal to the remote sites. If, however, a higher level of service is desired, such as having the ability to monitor performance and/or control flow of the broadcast signal, the invention provides the flexibility to encapsulate the broadcast signal to take advantage of these and other features typically associated with wide area network signals.
Network access devices associated with the central site and the remote sites are non-proprietary, standards-based equipment. In other words, signals emerging from each device are based on industry standards and are in a non-proprietary format. In this way, the invention provides an advantage of facilitating hybrid satellite/terrestrial communications without requiring encoding and decoding signals in a proprietary format. Furthermore, off-the-shelf standards-based components, such as frame relay access devices (FRAD) and Very Small Aperture Terminal (VSAT) satellite connection equipment, can be implemented with little or no modification. This enables network customers to implement the present invention with minimal equipment costs by building on their existing equipment investments.
Other technical advantages are readily apparent to one of skill in the art from the attached figures, description, and claims.